var min=9;
var max=30;
var element_id = "content";

function getCookie(c_name) {
  if (document.cookie.length>0) {
    c_start=document.cookie.indexOf(c_name + "=");
      if (c_start!=-1) { 
    	c_start=c_start + c_name.length+1; 
    	c_end=document.cookie.indexOf(";",c_start);
    	if (c_end==-1) c_end=document.cookie.length;
    		return unescape(document.cookie.substring(c_start,c_end));
    	} 
  	}
  return "";
}

function setCookie(c_name,value,expiredays) {
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+((expiredays==null) ? "" : "; expires="+exdate.toGMTString());
}

function checkCookie() {
	s=getCookie('fontSize');
	if (s!=null && s!="") {
	  document.getElementById(element_id).style.fontSize = s+"px"
	}
}

function increaseFontSize() {
	var div = document.getElementById(element_id);
	if(document.getElementById(element_id).style.fontSize) {
		var s = parseInt(document.getElementById(element_id).style.fontSize.replace("px",""));
	} else {
    	var s = 13;
    }
    if(s!=max) {
    	s += 1;
    }
    document.getElementById(element_id).style.fontSize = s+"px"
	setCookie('fontSize',s,365);
}

function decreaseFontSize() {
	var div = document.getElementById(element_id);
	if(document.getElementById(element_id).style.fontSize) {
		var s = parseInt(document.getElementById(element_id).style.fontSize.replace("px",""));
	} else {
		var s = 13;
	}
    if(s!=min) {
    	s -= 1;
    }
    document.getElementById(element_id).style.fontSize = s+"px"
	setCookie('fontSize',s,365);
}

function resetFontSize() {
	s = 13;
    document.getElementById(element_id).style.fontSize = s+"px"
	setCookie('fontSize',s,365);
}